Dasher

Dasher is an information-efficient text-entry interface,
driven by natural continuous pointing gestures.
Dasher is a competitive text-entry system wherever
a full-size keyboard cannot be used - for example,

when operating a computer one-handed, by joystick, touchscreen, trackball, or mouse;

when operating a computer with zero hands (i.e., by head-mouse or by eyetracker);

on a palmtop computer;

on a wearable computer.

The eyetracking version of Dasher allows an experienced user to write text
as fast as normal handwriting - 29 words per minute;
using a mouse, experienced users can write at 39 words per minute.